1. Field of the Invention
The invention relates to a seat depth adjustment device for a vehicle seat.
2. Description of the Related Art
Seat depth adjustment devices for vehicle seats are known. A support is formed on a seat structure and is moveable relative to the seat structure to vary a seat depth of the seat structure. The support can be adjusted mechanically or with the aid of an electric drive.
DE 20 2013 102 108 U1 discloses a seat depth adjustment device with a basic support and a support plate. The support plate is pretensioned toward the basic support with the aid of a spring to simplify manual operation of an adjustment of the seat cushion depth.
DE 10 2009 012 780 B3 discloses a seat depth adjustment device with a basic support connected fixedly to a seat structure. A support plate is on the basic support and is displaceable relative to the basic support with the aid of an electric drive.
EP 1 984 206 B1 relates to a seat depth adjustment device wherein the seat cushion adjustment has an electric drive for relative displacement of a support plate on a seat structure. The support plate is moveable relative to the seat structure, and therefore a seat depth of the seat structure can be changed. In addition, a spring is formed to assist the relative displacement. A cover return for adapting an upholstery cover is formed structurally and functionally with the seat cushion adjustment. The cover return is formed with the aid of a plate that has a perforated toothing and is accommodated moveably on the basic support. The plate is moved relative to the basic support via a pinion that is accommodated on the basic support and is connected mechanically to the perforated toothing. A rod is connected at both ends to the upholstery cover and is fastened to the plate. The rod is formed transversely with respect to a direction of movement of the support plate. During a movement of the support plate, the plate is moved with the aid of the pinion engaging in the perforated toothing, and therefore the rod is moved relative to the seat structure in a manner corresponding to the direction of movement via the movement of the plate. An annoying noise occurs during a movement of the plate because of the pinion engaging in the perforated toothing and meshing between the perforated toothing and the pinion.
It is an object of the invention to provide a seat depth adjustment device for a vehicle seat, with a cover return that is free from noise.